1 Biology 181, Sections 1, 2H, 3, 4H Drs. Richard Hallick and William Grimes Exam 2, Oct. 12, 2005 VERSION ONE 1) Explain why in anaerobic cells the ratio of pyruvate/ lactate is much less than one while under aerobic conditions the ratio of pyruvate/ lactate is much greater than one. a) lactate is produced from pyruvate under anaerobic conditions b) lactate is produced during the citric acid cycle in the absence of oxygen c) pyruvate is rapidly produced by the citric acid cycle d) oxidative phosphorylation transfers electrons to lactate to produce pyruvate e) under anaerobic conditions, pyruvate is converted to CO 2 2) Yeast produce ethanol and animals produce lactic acid in the ______ reaction which functions to produce ________ for anaerobic glycolysis. a) glycolysis, ATP b) citric acid cycle, NADH c) fermentation, NADH d) oxidative phosphorylation, ATP e) fermentation, NAD + 3) Why do the metabolic reactions in mitochondria require oxygen? a) fermentation cannot take place under anaerobic conditions b) glycolysis cannot produce pyruvate for metabolism in mitochondria without oxygen c) NAD + and FAD levels would be depleted without oxygen as an electron acceptor d) the citric acid cycle requires oxygen as a reactant e) photons are unable to split water and generate a proton gradient without oxygen 4) The metabolic reactions of glycolysis, pyruvate oxidation, and the citric acid cycle convert the carbons of glucose to CO 2 forming ATP and reduced electron carriers. At this stage of metabolism, the majority of the energy released from the chemical bonds of glucose is present as: a) a dramatic increase in temperature in mitochondria b) CO 2 and water c) ATP, NADH, FADH 2 d) ADP, NAD + , FAD e) acetyl CoA and lactic acid 5) Which of the following statements about the metabolism of fatty acids is true? a) degraded by the reactions of glycolysis b) requires glycolysis and fermentation c) requires citric acid cycle, oxidative phosphorylation, and low oxygen d) occurs in mitochondria and requires the presence of oxygen e) requires glycolysis, pyruvate oxidation, citric acid cycle, and oxidative phosphorylation 6) Phosphofructokinase is an allosteric enzyme that is inhibited by ________ and activated by __________. a) NADH, NAD + b) ATP, AMP c) AMP, ATP d) CO2, FADH2 e) glucose, pyruvate 7) Photons of light are the energy source for the synthesis of glucose from CO 2 by plant chloroplasts. What is the energy source that reduces CO 2 and produces glucose for use in the metabolic reactions of glycolysis, the citric acid cycle, and oxidative phosphorylation in animals? a)

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